Nanomaterials, such as graphene and carbon nanotubes (CNTs), hold great potential as materials for electronic components, due to remarkable properties such as extremely high charge carrier mobilities and current densities. Single atomic layer thickness provides ultimate electrostatic geometry for scaling down field-effect transistors (FETs). FETs fabricated with graphene and CNTs have shown improved performance compared to conventional semiconductor devices of the same size, but the performance of FETs fabricated with these carbon nanomaterials is far from their theoretical potential.